Much of the electronic equipment of today includes the use of circuit boards having electrical components mounted thereto. A plurality of these boards (known as daughter boards) are electrically connected to a mother board or back plane. One means of interconnecting mother and daughter boards is to provide a connector along the edge of the daughter card that mates with a complementary connector on the mother board. The connector may be a straight mounted connector or a right angle mounted connector. The straight style connector is most often used when the boards are mounted in a horizontal orientation and the right angle connector is used when the mother and daughter boards are mounted in a perpendicular orientation.
In mounting connectors to boards, it is desirable to protect the mating portions of the terminals from solder and flux. One way to protect the mating terminals within the housing is to provide a sealing material or a piece of tape along the lower edge of the housing. The use of tape is particularly suitable for straight mounted connectors where the tape can be easily slid over the extending straight terminal tails, but tape is not especially suitable for terminals having right angle bends. Use of a sealant material, such as those disclosed in U.S. Pat. No. 4,935,454, is suitable for both straight mount and right mounted connectors when the wall of the housings through which the terminal solder tails exit is essentially flat such as found with straight mount connectors and some right angle mount connectors. The use of such a sealant is made more difficult by increasing the number of rows of terminals in the connector and/or providing housing structure between the adjacent rows of the connector to organize the terminal tails as the terminals exit the housing.
In many instances it is also desirable to provide the assembled circuit board with its components with a conformable coating material to seal and protect the devices from environmental contamination. The coating over all the components by a variety of methods such as, for example, dipping, spraying, and painting with the preferred method being dipping. Regardless of the method used, however, it is important that the viscous liquid not enter into the matable interface of the electrical connector. In the dipping method, the board is held such that the connector remains above the solution. The solution then coats all surfaces of the board except for the mating connector.
It is desirable, therefore, to have a means for preventing the conformal coating material from entering the mating terminal of connectors having the more complicated housing structure.
It is also desirable to have a means for protecting the matable interface of the connector that is compatible for use with automated processes.
In assembling circuit boards, the components and connector are mounted to one side of the board such that leads extend into the through-holes of the circuit board and are soldered to the circuit board along the lower or opposite surface thereof by methods such as wave soldering or the like. Problems associated with flux and solder materials entering the connector housing when alleviated with right angle mounted connectors since there is a longer length of terminal between the board through-hole and the mating portion of the terminal. In applying the coating material by the dipping method, however, coating material is applied to both surfaces simultaneously and if the coating gets sufficiently near to the connector some of the material will travel along the terminals and may migrate into the connector thereby rendering the mating portion of the connector unusable.